262 REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 
1 his organ considerably. After each moult the markings of the dorsum are very dis- 
tinct, and the body is lead or mouse color, growing darker with each moult, but in 
the intervals fading to a silver-gray. The larva were lost September 6, at which time 
they had undergone five or six molts, but were not over one-third grown. 
Asilid-flies. — We .are not aware that the mode of egg-laying in these 
flies, or the nature of the eggs, have hitherto been recorded. Mr. Hub- 
bard, during his work for the Commission, succeeded in watching the 
operation in a Florida species (Mallophora orcina Wied.), and has made 
the following notes thereon : 
On September 3 or 4, while in the held, a species of Mallophora came dying and 
alighted in an open space between the rows of cotton. She seemed to have selected 
this spot at one glance as a suitable place in which to deposit her eggs, for without 
more ado she applied her abdomen to the 1 surface of the ground and began working it 
into the earth with a slight oscillating movement. In two or three minutes she had 
buried it to its base. Tho eggs must have been very rapidly laid, for after a few mo- 
ments she withdrew her body, filled up the hole with her abdomen, aided by her claws, 
brushed the surface carefully with the hairy tip of her body, and flew away. The en- 
tire proceeding occupied not more than four minutes, and the place of deposit was so 
carefully concealed that, although from my position six or eight feet distant I marked 
the exact spot with my eye, and immediately after drew a circle around it with my 
knife-blade, I could not detect tho slightest disturbance of the surface. The soil was 
a tenacious clayey loam. I removed in one lump the earth within the circle made by 
my knife, and, on breaking it open, found five or six eggs, packed in a not very close 
cluster, at a depth of $ to J of an inch. I placed the lump of earth containing the eggs 
in a metal box, where I found the young larva> in the act of hatching a week later. 
The eggs are yellowish-white, elongate, rounded at the ends, and, though not very 
carefully examined, seemed to present no remarkable structure, but resemble the eggs 
of some of the smaller crickets. 
Bee-fly larvae (Fanrily Bombyliidce). — We now come to the inter- 
esting and hitherto unrecorded life-history of two species of bee-flies, a 
family of two-winged flies that have a rapid darting flight and hover 
over flowers, from which they extract nectar by means of a long proboscis 
which characterizes most species. They derive the popular name from 
their hairiness and resemblance to bees, a resemblance enhanced by the 
humming which they produce in flight. On p. 303 of our First Report 
we figured an undetermined egg-parasite of the Rocky Mountain Locust, 
giving some account of its extensive occurrence in and about the egg- 
pods of that insect, and showing that next to the Anthomyia egg-para- 
site it was the most important enemy of the locust. The larva was 
somewhat anomalous. We were in doubt even as to what order of in- 
sects it belonged, placing it at the time in the Hymenoptera, and with a 
question among the Ichneumonidce. From the absence of spiracles on 
the intermediate abdominal joints we suspected, soon after the publica- 
tion of our First Report, that this larva would prove to be Dipterous 
rather than Hymenopterous. 
From such poor descriptions and figures as were extant, that most 
nearly approached it, we deemed it might be Anthracid, and were sub- 
sequently confirmed in this view by obtaining in October, 1879, a single 
pupa from a lot of larvse sent us by Mr. G. M. Dodge, of Gleucoe, Nebr. 
